The present invention relates to electrical connectors and in particular to a solder post retention system for preventing axial movement of solder posts once assembled into right angle mounted connectors.
Right angle connectors are typically mounted on a printed circuit board. A complementary connector mates with the right angle connector in a direction parallel to the printed circuit board. Contacts in the right angle connector have a mating portion that is parallel to the printed circuit board and a mounting portion that is in electrical contact with circuits on the printed circuit board with the mounting portion, typically a solder tail, extending from the mounting face of the connector substantially at a right angle to the mating portion of the contact. Solder tails typically extend through plated through holes in the printed circuit board and are soldered. The array of printed circuit board through holes has the same pattern and spacing as the solder tails extending from the mating face of the connector.
Maintaining the position of solder posts has been recognized as desirable for some time and permits predrilling of the array of holes in the printed circuit board knowing that the solder posts of a connector will correspond in position. Most attention has been given to maintaining the horizontal position of the solder posts. Various approaches have been taken in the prior art such as to make the connector housing in multiple parts, one of which is a locator plate having an array of apertures corresponding to the pattern and spacing of the solder tails extending from the mounting face of the connector. After all of the contacts are inserted into the connector housing, the locator plate is passed over the solder tails from the ends thereof and secured to the connector housing. U.S. Pat. No. 4,080,041 is typical.
Other positions maintaining techniques known in the prior art use a slotted locator plate. With the contacts inserted into contact receiving passages in a connector, the solder tails are bent into the slots of the locator plate such as disclosed in U.S. Pat. No. 4,697,864 or U.S. Pat. No. 4,491,376 which issued to Gladd et al and employs a slotted locator plate in which the slots are narrower in width than the solder tails.
All of the above prior art focuses on maintaining the horizontal position of the solder tails. Insufficient attention has been focused on maintaining the vertical position of solder tails, particularly in right angle connectors.
U.S. Pat. No. 4,225,209 discloses a right angle connector in which conductors are received in spaced-apart channels with alternate channels being relatively deep. The sidewalls of the channels are provided with depressions or recesses which receive barbs integral with and extending laterally from the side edges of the conductors. The intermediate portions of the conductors which extend from apertures to the channels are thus held rigidly by the barbs in the channels and by the conductors received in the apertures.
U.S. Pat. No. 4,550,962 discloses a right angle connector without a locator plate having stop members formed to define stop shoulders on the contact pins to prevent the contact pins from being inserted too far into printed circuit board through holes in which the connector is mounted.
Horizontal positioning of connector solder tails has long been important for assuring that a mass produced connector having a predetermined solder tails pattern would be compatible with a mass produced printed circuit board having a corresponding array of plated through holes. Vertical position, although important, has been inspected upon manual insertion of the connector in a printed circuit board to assure the solder tails extended beyond the printed circuit board a sufficient distance to provide a good solder joint.
With the advent of robotic installation of connectors in printed circuit boards, maintaining the vertical position of solder tails such as during shipping and handling is more critical. For robotic assembly it is important to know precisely where each feature of a connector assembly is relative to a datum reference on the connector assembly. The location of an important feature is the end of the solder tails to assure that during robotic stuffing of a printed circuit board the solder tail ends enter a corresponding array of plated through holes in the printed circuit board. Should the solder tails ride up during insertion of the solder tails in the array of through holes such as due to stubbing, frictional engagement between a solder tail and a through hole, or due to a centering action as the tapered end of a solder tail is urged toward the center of a through hole, a sufficient length of the solder tail may not extend beyond the lower surface of the printed circuit board to provide an acceptable solder joint.
For example, for a 0.062 inch thick printed circuit board, the solder tails should extend 0.062 inch below the board for soldering. Upon assembly of a connector, the tip of the solder tails are therefore positioned 0.125 inch below the housing mounting face, with an allowance for a tolerance, and assure that the solder tails will extend beyond the printed circuit board an appropriate distance for an acceptable solder joint.
The present invention is directed toward providing a solder post retention system for maintaining solder posts in a predetermined position relative to a solder post spacer plate by preventing vertical movement of solder posts once assembled into right angle mounted connectors.